const a: number = 10;
console.log(a)

const str: string = 'hello';
console.log(str)

const flag: boolean = false;
console.log(flag)

const demo:string[] = ['a', 'b', 'c']
console.log(demo)

const demo02:(string|number)[] = ['123', 456]
console.log(demo02)

const obj:{name: string, age: number} = {name: '张三', age: 23};
console.log(obj.name)
